I have a JL XD500/3 powering an Infinity Kappa 120.9w. It was working fine, until yesterday I moved some things around - also messed with changing the input to a different input so mucked with the line sensitivity a little bit. Now all of a sudden the sub does not hit NEARLY as hard, even when reverting to the old input and input sensitivity settings. Now, I believe it is an issue with amp, but I am not sure. I thought maybe I knocked something loose in the sub box, but the sound doesn't pop in and out, it's just constantly low. I tested the resistance across the leads of the sub box and it is 2ohms steady as expected. Does this confirm that the culprit is the amplifier? When setting the gains on the amp I am able to get the voltage stated in the manual when running no load - this doesn't necessarily mean it is working correctly right?
Thanks in advance! Sorry if this is a noob question, I just want to be sure I am returning the right item to amazon and have done my due diligence in debugging. I don't have another amp or sub to swap out to test with.